What's the difference between plesiomorphic and primitive?
Plesiomorphic
Definition:
Example Sentences:
(1) Forty-six characters were coded in plesiomorphic and apomorphic states.
(2) Undecussated ipsilateral retinal projections, as present in the bowfin, are a widely distributed character in vertebrates and appear to be plesiomorphic for vertebrates.
(3) Clear synapomorphies with modern man combined with some plesiomorphic retentions indicate a slightly more primitive (and older?)
(4) This suggests that the circuitry in the intermediately complex pattern, as represented by Osteoglossum, is plesiomorphic (evolutionarily primitive) and the circuitry in both the simple pattern (seen in cyprinids) and the elaborate pattern (seen in percomorphs) is apomorphic (evolutionarily derived) for teleosts.
(5) The dorsomedial part of the lepidosirenid telencephalon corresponds to the septum in the most plesiomorphic living lungfish, Neoceratodus forsteri, but it differs considerably from the dorsomedial telencephalon (medial pallium) in amphibians.
(6) The posterior pretectal nucleus is relatively small in the bowfin, and the distribution of a small, versus a large, posterior pretectal nucleus in Teleostei and Halecomorphi suggests that this nucleus was small plesiomorphically.
(7) Direct-developing desmognathine salamanders have the plesiomorphic set of motor neurons, but appear to lack Mauthner neurons.
(8) A "bare" myocardium, as found on ontogenetic days 12 and 13 in Tupaia, might be a primitive (plesiomorphic) condition among chordates.
(9) This represents a true plesiomorphous character state in therian ontogeny.
(10) Species of Spirhapalum retained a relatively plesiomorphic distribution, and they are found in emydids (Europe) and batagurids (Asia).
(11) Comparison of the gene content of other fish, amphibians, and mammal syntenic groups suggests retention of plesiomorphic vertebrate gene arrangements in at least two poeciliid linkage groups.
(12) This plesiomorphic karyotype consists of acrocentric chromosomes 1, 2, 5, 6, 8, 9, and 10; submetacentric chromosomes 3 and 4; and a metacentric chromosome 7.
(13) It is hypothesised that this 2n = 22 complement is plesiomorphic for all macropodids.
(14) This study was done to elucidate the ancestral (plesiomorphic) condition for visual pathways to the hypothalamus in teleost fishes.
(15) These response types are very similar to those found in amphibians; therefore, it is concluded that tectal configurational sensitivity may be a plesiomorphic tetrapod character resulting from basic properties of tectal neuronal circuitry.
(16) Ect-aquasperm are the commonest type of polychaete sperm and are considered plesiomorphic for the Polychaeta.
(17) In the plesiomorphic state, represented by species with aquatic larvae, five types of motor neurons are present: (1) large, multipolar neurons, believed to be primary motor neurons; (2) medial, pear-shaped neurons; (3) larger, spindle-shaped neurons, which increase in number during posthatching development; (4) cone-shaped neurons, and (5) bilaterally arborizing neurons (found only at the rostral pole of the first spinal nucleus).
(18) It should now be possible to relate the G-banding patterns of all other Petrogale species to this plesiomorphic complement and thereby determine the number and types of changes that have occurred during the course of chromosome evolution in Petrogale.
(19) The taxonomic distribution of the pretectal patterns indicates that the simple and the elaborate patterns are both evolutionarily derived (apomorphic) from the primitive (plesiomorphic) intermediately complex one.
(20) The 2s, 5s, 4sm, and 8m chromosomes all appear to be derived from their plesiomorphic homologs by centromeric transpositions.
Primitive
Definition:
(a.) Of or pertaining to the beginning or origin, or to early times; original; primordial; primeval; first; as, primitive innocence; the primitive church.
(a.) Of or pertaining to a former time; old-fashioned; characterized by simplicity; as, a primitive style of dress.
(a.) Original; primary; radical; not derived; as, primitive verb in grammar.
(n.) An original or primary word; a word not derived from another; -- opposed to derivative.
Example Sentences:
(1) Cloacal exstrophy, centered on the maldevelopment of the primitive streak mesoderm and cloacal membrane, results in bladder and intestinal exstrophy, omphalocele, gender confusion, and hindgut deformity.
(2) Evx-1 RNA is first detected shortly before the onset of gastrulation in a region of ectoderm containing cells that will soon be found in the primitive streak.
(3) As an extension of the previous study which indicated that mesoglea is a primitive basement membrane which has retained some characteristics of interstitial extracellular matrix, the present study was undertaken to analyze the role of mesoglea components during head regeneration in Hydra vulgaris.
(4) neuroblastomas, primitive neuroectodermal tumours (PNETs), rhabdomyosarcomas and malignant lymphomas.
(5) We concluded that the primitive eukaryote D.discoideum contains proteins which show functional and physical similarity with the alpha-subunits of vertebrate G-proteins.
(6) Mechanisms are suggested whereby rudimentary appetitive programs already encoded along facing dendrite membrane pairs within the specialized intrafascicular milieu, may trigger and control nipple search and suckling in the still blind and only primitively mobile neonate.
(7) Thus, the progeny of infected primitive multipotential cells are competent to express integrated proviruses.
(8) Multiple tuberculomas have simulated either an alcoolic encephalopathy in one case or a primitive cerebral tumour in another one.
(9) This increased cell flow down the early stages of the red cell pathway in CML suggests that heightened proliferation and differentiation of primitive hemopoietic cells may be a more general phenomenon than previously suspected in this disease.
(10) The Lerner & Lerner Scale for assessing primitive defenses is reviewed.
(11) Only tumors of astrocytic lineage like astrocytomas and glioblastomas, or tumors of mixed lineage as oligo-astrocytomas and multipotential primitive neuroectodermal tumors (PNET) expressed TNF-alpha-like immunoreactivity.
(12) This epithelial cell was tentatively identified as primitive extraembryonic endoderm by its ultrastructural appearance and its possession of cytokeratin intermediate filaments.
(13) The long-term culture corresponded to mouse MXT and MCF-7 cell lines whereas the primary culture corresponded to primitive breast cancers squashed onto histologic slides and maintained in cultures for between 12 and 48 h. Cell proliferation was evaluated by means of digital cell image analysis of Feulgen-stained nuclei.
(14) From these facts, it was concluded that the follicular, as well as acanthomatous, ameloblastoma is liable to undergo squamous differentiation, whereas the plexiform ameloblastoma remains in primitive stage of tumor differentiation.
(15) A cluster of spermatogonia may be derived from one primitive germ cell and it develops round a "Sertoli" cell.
(16) Shielded marrow self renewal capacity, a measurement reflecting primitive hematopoietic stem cell function, remained depressed and did not recover with time.
(17) In a 3-year-old child, a rare combination of a Dandy-Walker syndrome, a primitive trigeminal artery and a facial haemangioma was found.
(18) As the histochemical and ultrastructural findings are non specific, we believe, according to recent opinions, that this tumor could originate in a very primitive cell, able to differentiate to endocrine or exocrine elements, almost always incompletely.
(19) It is likely that the development of these malignancies is an expression of the multipotential nature of primitive germ cells.
(20) Morphology of the mature spermatozoon is modified from that of the classic primitive or ect-aquasperm type by having 1) the acrosome embedded in the nucleus (the only known example within the Mollusca), 2) a deep basal invagination in the nucleus containing proximal and distal centrioles and an enveloping matrix (derived from the rootlet), 3) laterally displaced periaxonemal mitochondria, and 4) a tail extending from the basal invagination of the nucleus.